学步园

public class ChangeCode {

    public static void main(String[] args) {

        String QJstr = "abcdefghijklmnopqrstuvwxyz,.'?";
        String QJstr2="ａｂｃｄｅｆｇｈｉｊｋｌｍｎｏｐｑｒｓｔｕｖｗｘｙｚ";

        String result1 = Q2B(QJstr2);
        String result2 = B2Q(QJstr);

        System.out.println(result1);
        System.out.println("\n"+result2);
    }

    private static String Q2B(String QJstr) {// 全角-->半角
        String outStr = "";
        String Tstr = "";
        byte[] b = null;

        for (int i = 0; i < QJstr.length(); i++) {
            try {
                Tstr = QJstr.substring(i, i + 1);
                b = Tstr.getBytes("unicode");
            } catch (java.io.UnsupportedEncodingException e) {
                e.printStackTrace();
            }

            if (b[3] == -1) {
                b[2] = (byte) (b[2] + 32);
                b[3] = 0;

                try {
                    outStr = outStr + new String(b, "unicode");
                } catch (java.io.UnsupportedEncodingException e) {
                    e.printStackTrace();
                }
            } else
                outStr = outStr + Tstr;
        }

        return outStr;
    }

    private static String B2Q(String QJstr){// 半角-->全角
        String outStr = "";
        String Tstr = "";
        byte[] b = null;

        for (int i = 0; i < QJstr.length(); i++) {
            try {
                Tstr = QJstr.substring(i, i + 1);
                b = Tstr.getBytes("unicode");
            } catch (java.io.UnsupportedEncodingException e) {
                e.printStackTrace();
           }

            System.out.println(Tstr);
            System.out.println("b[0]="+b[0]);
            System.out.println("b[1]="+b[1]);
            System.out.println("b[2]="+b[2]);
            System.out.println("b[3]="+b[3]);
            if (b[3] == 0) {
                b[2] = (byte) (b[2] - 32);
                b[3] = -1;

                try {
                    outStr = outStr + new String(b, "unicode");
                } catch (java.io.UnsupportedEncodingException e) {
                    e.printStackTrace();
                }
            } else
                outStr = outStr + Tstr;
        }

        return outStr;
    }
}